The DSM-IV criteria for mania require: a distinct period that represents a break from pre-morbid functioning, a duration of at least one week, elevated or irritable mood, at least three to four classical manic signs and symptoms and the absence of any physical factors. Although not specifically mentioned in the ICD-10 or the DSM-IV definitions, delusional, hallucinatory, even first-rank, psychotic experiences can occur in mania. Acute mania can be subdivided into classical pure mania, mania with mood-congruent or mood-incongruent psychosis, mixed state and rapid-cycling mania. One quarter to two thirds of all manic episodes are associated with delusions, while 13% to 40% are associated with hallucinations. Mixed episode is a complex syndrome which is difficult to diagnose, has the most prolonged duration of bipolar episodes and more frequent psychotic profile than pure mania with high suicidality and poor response to drugs. Mixed state mania has been well known since Kreapelin and listed in classification systems with criteria that include both a manic and a major depressive episode nearly every day for at least a one-week period. On the other hand, mixed-like episodes that are clearly caused by somatic antidepressant treatment (e.g., medication, electro-convulsive therapy or light therapy) should not contribute toward a diagnosis of Bipolar I Disorder. Although, theoretically, mania is supposed to be resolved within 1-3 months even without treatment, psychiatric hospitalization is very common in especially severe cases due to functional impairment. Current treatments for mania aim to control the agitation, impulsivity, aggression and psychotic symptoms and to help patients regain their pre-morbid functionality. However, the clinical management of mania is challenging as most patients show syndromal remission but incomplete functional recovery after the first episode of mania.